Objective: To provide theoretical basis and experimental ways for follow-up study, analysising the sequence signature, structure and receptor binding sites of FAS protein. Method: the sequence of FASLG protein was downloaded from NCBI database, which is studied by ProtParam，ProtScale，SignalP 4.1，TMHMM Server v. 2.0，ClustalX，SWISS-MODEL and AutoDock. Result: FASLG has 281 amine acids, which is alkaline, unstable hydrophilic and transmembrane protein. FASLG has no signal peptide and receptor binding cites of FAS. The 3D structure of FASLG consisted by 74 α helices，20 B sheets, 56 Extending segments and 131 coils. The FASLG protein couples with its receptor protein of FAS by 15amino acids，then they will form the FAS/FASLG signaling pathways to induce cell apoptosis. Conclusion: The sequence signature, 3D structure and receptor binding cites are obtained, which provides a new direction of studying the FAS/FASLG signaling pathway and knowing the role of miR-21 and FASLG in colon cancer cells.